This invention relates to synchronous motor drives, and particularly to drives for controlling a motor that guides the laying of windings on a coil winding mechanism.
A coil winding arrangement requires a transversely moving guide to move the wire transversely as it is wound upon a rotating coil form. Synchronism between the rotation of the coil and the movement of the guide may be maintained by mechanical linkages. However, these are often cumbersome. On the other hand, utilizing a separate motor for controlling the guide is rather difficult. The guide motor must be operated in synchronism with the motor that rotates the coil form. Such synchronism is not easily obtained without complicated equipment because the guide motor must be able to stop and start with the operation of the form rotating motor. Any delay may result in the wires being improperly laid.
Stepping motors are particularly useful for performing controlled functions of the type necessary in such coil winding machines. This is so because stepping motors respond to input pulses which can be accurately counted. These pulses move the motor over accurate angular distances. However, stepping motors still have inertial delays. When such motors are stopped, pulses applied too rapidly fail to move the motor at all. Such pulses are then lost, to the detriment of the desired accuracy.
An object of the present invention is to overcome these difficulties.
Another object of the invention is to provide a drive for stepping motors.